When manufacturing knit or Jersey knit goods on latch needle type knitting machines, for example circular knitting machines, the latches of the latch needles are forcibly opened, so that the last-formed stitches or loops slide along the shank of the needles from the needle hook. The last-formed stitches or loops thus effect the opening of the latches, thereafter sliding over the head of the latches onto the needle shank. Current high-performance knitting machines, for example, may have three to four feeds per nominal inch diameter. Such high density of knitting feeds requires cam races or cam tracks engaging the butts of the needles such that the raising cams have a comparatively steep needle projection angle and, thereafter, the lowering cams likewise have a steep angle. This rapid projection and retraction, respectively, of the needles results in very fast opening of the latches of the needles. Typically, the opening process is already terminated while the needle passes through one needle division or cut. In a circular knitting machine of 30" nominal diameter, and having a circumferential speed of, for example, 1.2 m/sec, the speed of movement of the latch of the latch needle may reach 30 m/sec. These high speeds of operation of the latch elements of the needles result in substantial engagement speeds or forces, and particularly in substantial speed at the tip of the latches against the shank, or the hook ends, respectively, which, of course, provide for high loading of the needles and especially of the latches. This substantial stress placed on the latches results in deformation and breaks of portions of the needle heads or the shank portion in the region of engagement of the latches when pivoting backwardly.
It has been proposed to improve the needles to be able to accept the high forces, and the high speeds which must be stopped practically instantaneously. Special high-speed needles were developed which, by special construction, provide for elastic damping of the latch, and specifically the impacts of the latch when it is completely opened and is flipped backwardly against the needle shaft. The inertia mass of the latch of the needle, decrease of the length of the latch from the pivot point thereof, and the like, also have been used in order to decrease the high dynamic loading on the needles. Yet, it has been found that the limit of operating speed which can be reached is determined by the maximum stresses which can be placed on the needles.